Drum type washing machine

ABSTRACT

The present invention relates to a direct type driving part of a drum type washing machine. A drum type washing machine includes a tub mounted in a housing to hold wash water therein; a drum rotatably mounted in the tub; a rotor connected to a rotational shaft of the drum; a bearing housing including a bearing for supporting the rotational shaft of the rotor, the bearing housing positioned at the tub; a stator connected to the tub, spaced apart in a predetermined distance from the rotor; and a motor mounter positioned on a rear surface of the tub, the motor mounter coupled to the stator.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No. 10-2006-0068111, filed on Jul. 20, 2006, which is hereby incorporated by reference as if fully set forth herein.

BACKGROUND OF THE DISCLOSURE

1. Field of the Disclosure

The present invention relates to a drum type washing machine. More particularly, the present invention relates to a direct type driving part of a drum type washing machine.

2. Discussion of the Related Art

According to a drum type washing method, washing is typically performed by using friction force between a drum rotated by a motor and laundry, in a state of detergent, wash water, and laundry being mixedly introduced in the drum. As a result, the drum type washing method has less damage to laundry, less entanglement of laundry and a washing effect as if the laundry were scrubbed and washed by human hands.

Conventional drum type washing machines are classified, based on a driving method of a motor, into indirect driven drum type washing machines and direct driven drum type washing machines. In an indirect driven drum type washing machine, a driving force of a motor is indirectly transmitted to a drum through a motor pulley and a motor belt wound around a drum pulley. In a direct driven drum type washing machine, a rotor of a BLDC motor is directly connected to a drum to transmit a driving force of the motor to the drum.

Here, in the indirect driven drum type washing machine, there is a problem of energy loss and much noise during the transmission of the driving force. Thus, to solve the problem of the indirect driven drum type washing machine, the direct driven drum type washing machine has been used more and more recently in which a motor is mounted to a rear wall of a tub to directly transmit the driving force of the motor to a drum.

In reference to FIG. 1, a structure of a conventional direct driven drum type washing machine will be explained schematically.

FIG. 1 is a longitudinally sectional view illustrating a structure of the conventional drum type washing machine. As shown in FIG. 1, a tub 2 is mounted in a cabinet 1 and a drum 3 is rotatable in the tub 2.

A motor is mounted to a rear portion of the tub 2. A stator 6 of the motor is fixed to a rear wall of the tub 2 and a rotor 5 of the motor passes through the tub 2 to be shaft-connected to the drum 3, covering the stator 6.

Together with that, a tub supporter having a corresponding shape to the rear wall of the tub is provided between the rear wall of the tub 2 and the stator 6 to support load of the stator as well as to maintain concentricity of the stator when the stator is coupled to the rear wall. The tub supporter is formed by pressing a steel plate and it covers most of the rear wall.

Meanwhile, a door 21 is coupled to a front of the cabinet 1 and a gasket 22 is provided between the door 21 and the tub 2.

A hanging spring 23 is provided between an inner upper surface of the cabinet 1 and an outer upper surface of the tub 2 to supportingly hang the tub 2. A friction damper 24 is provided between an inner lower surface of the cabinet 1 and an outer lower surface of the tub 2 to dampen vibration of the tub, which may be produced in a spinning cycle.

FIG. 2 is a perspective view illustrating an exterior of the stator shown in FIG. 1 and FIG. 3 is a perspective view illustrating a DC (Divided Core) applied to the stator of FIG. 2. According to a manufacturing method of a conventional stator, a steel plate is pressed and unit cores are formed, with a base 150, tooth 151 and protrusions 500 projected to form coupling holes 500 a. The protrusions 500 are opposite to the tooth 151. Hence, the unit cores are layered to form a core assembly and the core assemblies are inter-connected in a radial direction, such that a stator core called as a DC is formed.

At this time, the protrusions 500 are employed for providing coupling holes 500 a needed when the stator 6 is coupled to the rear wall of the tub 2 and for allowing the DC to stand a coupling force of a bolt. That is, the protrusion 500 is formed of the steel plate.

However, the above conventional manufacturing method of the stator 6 by using such DC has complex processes and a lot of material loss. Moreover, an overall weight of the stator is increasing because of the weight of the protrusions 500.

As mentioned above, the metal tub supporter should be provided between the rear wall of the tub and the stator to fix the conventional stator 6 to the rear wall of the tub. Specifically, the tub supporter shaped corresponding to the rear wall of the tub is necessary to enhance a coupling strength between the relatively heavy stator and the rear wall of the tub.

Furthermore, it is difficult to manufacture the tub supporter having the corresponding shape to the rear wall of the tub and it takes a lot of processes to couple such tub supporter to the rear wall of the tub. Since such tub supporter is formed of steel plate and it covers most of the rear wall, the weight of the tub support is quite heavy. As a result, it is not appropriate that such tub supporter is coupled to the rear wall of the tub to maintain the concentricity of the stator 6.

Accordingly, demands have been increasing for a lighter stator as well as for a method of fixing a stator to a tub securely.

SUMMARY OF THE DISCLOSURE

Accordingly, the present invention is directed to a drum type washing machine.

An object of the present invention is to provide a drum type washing machine with reduced material consumption and lighter weight and a simple production process, which includes an outer rotor type motor configured of a stator securely coupled to the tub.

Another object of the present invention is to provide a drum type washing machine with a simple assembly process, which can secure a supporting force of the stator coupled to a rear wall of a tub.

Additional advantages, objects, and features of the disclosure will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a drum type washing machine includes a tub mounted in a housing to hold wash water therein; a drum rotatably mounted in the tub; a rotor connected to a rotational shaft of the drum; a bearing housing including a bearing for supporting the rotational shaft of the rotor, the bearing housing positioned at the tub; a stator connected to the tub, spaced apart in a predetermined distance from the rotor; and a motor mounter positioned on a rear surface of the tub, the motor mounter coupled to the stator.

The bearing housing may be formed as one body with the tub.

A hub may be projected outwardly at a center of a rear surface of the tub. The bearing housing may be positioned at the tub, passing through the hub.

Unevenness may be formed on an outer circumferential surface of the bearing housing and an inner circumferential surface of the tub in a circumferential or extent direction, respectively.

In the meantime, the motor mounter may be coupled to the tub, spaced apart a predetermined distance from the bearing housing in a radial direction.

Here, the motor mounter may be ring-shaped.

The motor mounter includes a ring-shaped plane part; and a side surface projected perpendicularly toward the tub from the plane part.

The side surface may be formed at on least one of an inner portion or an outer portion of the plane part with respect to a radial direction of the plane part.

A coupling part may be formed at the stator, coupled to the tub and the motor mounter. A coupling hole corresponding to the coupling part may be formed at the motor mounter.

In addition, the motor mounter may include a tub coupling hole coupled to the tub.

A seating part may be formed at a rear surface of the tub and the motor mounter may be seated on the seating part. The seating part may have a shape corresponding to the motor mounter.

The motor mounter may include a plurality of reinforcement ribs that extend along a circumferential direction. In this case, the motor mounter may be formed of a steel plate. The reinforcing rib may be formed by a lancing process.

The motor mounter may be configured of a plurality of modules. The plurality of the modules may be connected each other.

At least a predetermined portion of the motor mounter may be insert-molded in the tub. In this case, an upper portion of the motor mounter may be exposed when the motor mounter is insert-molded in the tub. A coupling hole to which the stator is coupled may be formed at the motor mounter. The motor mounter may be insert-molded, the coupling hole being exposed outside the tub.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the disclosure and together with the description serve to explain the principle of the disclosure. In the drawings:

FIG. 1 is a longitudinally sectional view schematically illustrating a structure of a conventional direct driven drum type washing machine;

FIG. 2 is a perspective view illustrating a structure of a conventional stator;

FIG. 3 is a perspective view illustrating a DC shown in FIG. 2;

FIG. 4 is a longitudinally sectional view schematically illustrating a structure of a direct driven drum type washing machine according to the present invention;

FIG. 5 is an enlarged view of ‘A’ shown in FIG. 4, which is longitudinally sectional view illustrating a driving part of the drum type washing machine according to the present invention;

FIG. 6 is a perspective view illustrating a motor mounter applied to the present invention, seen from below;

FIG. 7 is a perspective view illustrating the motor mounter of FIG. 6, seen from above;

FIG. 8 is a sectional view illustrating a cut-away part of AA shown in FIG. 6;

FIG. 9 is sectional view illustrating an reinforcing rib shown in FIG. 8;

FIG. 10 is a front view illustrating a base of the tub shown in FIG. 5;

FIG. 11 is a perspective view illustrating a stator of FIG. 5;

FIG. 12 is a perspective view illustrating a spiral core of FIG. 10;

FIG. 13 is a plane view illustrating key parts of the stator shown in FIG. 11; and

FIG. 14 is a perspective view illustrating key parts of the stator shown in FIG. 11.

DESCRIPTION OF SPECIFIC EMBODIMENTS

Reference will now be made in detail to the specific embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

FIG. 4 is a longitudinally sectional view schematically illustrating a structure of a direct driven drum type washing machine according to the present invention. FIG. 5 is an enlarged view of ‘A’ shown in FIG. 4, which is longitudinally sectional view illustrating a driving part of the drum type washing machine according to the present invention.

A drum type washing machine according to the present invention includes a motor, a tub 2 and a bearing housing 7. The motor is configured of a rotor 5 and a stator 6. The tub 2 is mounted in a cabinet 1 to hold wash water therein and it has a base 2 a to which the stator 6 is coupled. The bearing housing 7 holds a bearing that supports a rotational shaft of the rotor 5.

The drum type washing machine according to the present invention further includes a drum 3 selectively rotatable in the tub and a shaft 4 connected to the rotor 5 to transmit a driving force of the motor to the drum 3. Here, the laundry is loaded in the drum 3.

It is preferable that the tub 5 is formed of plastic. It is also preferable that the bearing housing 7 formed of metal is provided at a rear wall of the tub 2. The rear wall of the tub 2 is, specifically, a center of a tub base to support the bearing provided at each outer circumferential surface of both opposite ends of the shaft 4.

At this time, the bearing housing 7 is formed of aluminum alloy and it is insert-molded when the plastic tub 2 is injection-molded, such that the bearing housing 7 is formed as one body with the tub base 2 a. In addition, it is possible to couple the bearing housing 7 to the tub base 2 a by using a bolt.

In reference to FIG. 5 that is an enlarged view of “A” of FIG. 4, the bearing housing 7 is configured as a sleeve to support the bearing. Bearings 600 a and 600 b are provided inside the bearing housing 7 to rotatably support the shaft 4.

The bearing housing 7 is insert-molded in the tub and passes through a center of the tub base 2 a so that the bearing housing 7 is formed as one body with the tub 2.

Here, it is preferable that unevenness 7 a is formed on an outer circumferential surface of the bearing housing 7. The unevenness 7 a enables a coupling strength between the bearing housing and the tub base to be enhanced. The unevenness 7 a may be formed along a circumferential direction of the outer circumferential surface of the bearing housing 7, or may be formed along an extent direction of the outer circumferential surface. Also, the unevenness 7 a may be formed along the circumferential direction and the extent direction of the outer circumferential surface at the same time.

The unevenness 7 a formed along the extent direction may enhance a coupling strength with respect to the extent direction between the bearing housing 7 and the center of the tub 2. The unevenness 7 a formed along the circumferential direction may enhance a coupling strength with respect to the circumferential direction between the bearing housing 7 and the center of the tub 2.

The shaft 4 is provided through a center of the bearing housing 7. An end of the shaft 4 is connected to the drum 3 and the other opposite end of the shaft 4 is connected to the rotor 5.

The end of the shaft 4 is connected to the drum 3 through a spider 10 to transmit a rotational force to the drum 3 more reliably. A bushing 11 is inserted in a predetermined portion of the shaft 4 that is from an exposed portion to a rear of the spider 10 to the bearing 600 a, and the bushing 11 is formed of brass to prevent rust of the shaft 4. A sealing member 12 is provided at an outer surface of the bushing 11 to prevent moisture from penetrating through the bearing.

By the way, the rotor 5 is coupled to a rear end center of the shaft 4, which is configured of a direct driven motor, and the stator 6 is positioned in the rotor 5 and it is coupled to the rear wall of the tub 2, which is configured of the direct driven motor together with the rotor 5.

The rotor 5 is formed of steel plate. A curvature is formed along a circumferential direction on a side surface 13 b of the rotor 5 and the curvature has a seating surface 130 in which a magnet M mounted on the seating surface 130. Here, the side surface 13 b extends forward from a predetermined portion of a rear surface 13 a of the rotor 5. In addition, a hub 132 is formed at a center of the rear surface 13 a and a through hole 131 is formed at the hub 132. Here, a coupling member 15 a such as a bolt for coupling the rotor 5 to the shaft 4 is able to pass the through hole 131.

It is preferable that an overall appearance of the rotor 5 is formed by pressing.

A plurality of cooling pins 133 may be formed near the tub 132 of the rotor 5 in a radial direction, respectively, and the cooling pins 133 blows air toward the stator 6 to cool the heat of the stator 6 during the rotation of the rotor 5. At this time, the cooling pins 133 have a predetermined length in a radial direction, respectively.

The cooling pin 133 is bent at the degree of 90° with respect to the rear surface 13 a toward an opening of the rotor 5 by a lancing process and a through hole 134 formed by the lancing process is employed as a ventilating opening.

In addition, an embossing 135 is formed between each cooling pin 133 of the rear surface 13 a and each neighboring cooling pin 133 to reinforce the strength of the rotor 5. A water drain hole 136 is formed on the embossing 135 and water is drained through the water drain hole 136.

A connector 16 is provided adjacent to the through hole 131 formed at the tub 132 and the connector 16 is serration-connected to an outer circumferential surface of the rear end of the shaft 4 exposed to a rear of a rear bearing 600 b.

The connector 16 is formed of resin having a different vibration mode from the steel rotor 5 and it is employed to be a bushing for the rotor 5 and to insulate heat between the rotor 5, or stator 6, and the shaft 4.

A serration 164 is formed at an inner circumferential surface of the connector 16, corresponding to a serration 400 formed at a rear end of the shaft 4.

A hub 2 b is formed on the base 2 a of the tub 2 and the bearing housing 7 is insert-molded in the hub 2 b when the tub 2 is injection-molded.

The motor mounter 300 is provided, spaced apart a predetermined distance from the bearing housing 7 of the tub 2 b in a radial direction. Here, it is preferable that the motor mounter 300 is spaced apart a predetermined distance from the hub 2 b in a radial direction.

The stator 6 is mounted to the motor mounter 300. The stator 6 may be mounted to the motor mounter 300 and coupled to the base 2 a of the tub 2 at the same time.

FIG. 6 is a perspective view illustrating an example of the motor mounter and FIG. 7 is a perspective view illustrating the motor mounter shown in FIG. 6, seen from below.

As shown in FIGS. 6 and 7, the motor mounter 300 is formed substantially in a ring shape and a plane part 313 is formed at the motor mounter 300. It is preferable that the plane part 313 is formed substantially in a ring shape, because the pane part 131 is coupled to the base 2 a of the tub 2 to be perpendicular to the shaft 4 and thus the stator 6 is coupled to the tub 2 securely.

The motor mounter 300 includes a coupling part, especially, a coupling hole 320 to allow the motor mounter 300 coupled to the base 2 a of the tub 2. As a result, the motor mounter 300 is coupled to the base 2 a by a bolt or the like through the coupling hole 320. It is preferable that more than three coupling holes 320 are formed along a circumferential direction of the motor mounter 300.

In addition, the motor mounter 300 includes another coupling hole 310 and the stator 6 is coupled to the base 2 a of the tub 2 by a bolt or the like through the coupling hole 310. Here, more than three coupling holes 310 are formed along the circumferential surface of the motor mounter 300.

The coupling holes 320 and the coupling holes 310 maybe formed at the same circumference or at different circumferences. However, it is preferable on production sake that the coupling holes 320 and the coupling holes 310 are formed at the same circumference.

A position determination recess 314 is formed at a predetermined portion near the coupling hole 310 and a position determination protrusion 143 b (see FIG. 13) which will be described later is inserted in the position determination recess 314. It is preferable that the position determination recess has a hole shape.

Such position determination recess 314 is employed to secure a concentricity of the stator 6 when the stator 6 is coupled to the tub 2 as well as to prevent the stator 6 from being eccentric. As a result, an effect of motor noise reduction may be expected because of the position determination recess 314.

Here, the motor mounter 300 may be formed of metal, especially, steel plate to securely support the stator 6.

As shown in FIGS. 5 to 7, side surfaces 312 and 311 may be formed at an inner portion and an outer portion with respect to the radial direction of the plane part 313, respectively. The side surfaces 312 and 311 are inserted in the base 2 a of the tub 2 to enhance the coupling strength between the motor mounter 300 and the tub 2. As a result, the coupling strength between the stator 6 and the tub 2 may be enhanced too.

Such coupling between the motor mounter 300 and the tub 2 may be facilitated by a seating part formed at an outer surface of the base 2 a and the motor mounter 300 is seated on the seating part. It is preferable that the sectional shape of the seating part is corresponding to that of the motor mounter 300. It is also preferable that the coupling hole 320 for motor mounter or the coupling hole 310 for the stator 6 is formed at the seating part.

FIGS. 8 and 9 are sectional views illustrating another example of the motor mounter 300, specifically, illustrating another example of AA section shown in FIG. 6. There is no reinforcement rib formed at the motor mounter 300 shown in FIG. 6 along a circumferential direction. There is rib formed at the motor mounter shown in FIGS. 8 and 9. As shown in FIGS. 8 and 9, the side surfaces 312 and 311 may not be formed at the motor mounter 300.

The reinforcement rib 316 may be formed along the circumferential direction of the motor mounter 300 in plural. It is preferable that the reinforcement rib 316 may be formed at the plane part 313 between the coupling hole 310 and the coupling hole 320.

Such reinforcement rib 316 extends in a radial direction and perpendicular to the plane part 313. The reinforcement rub 316 is insertedly coupled to the base 2 a of the tub so that the coupling strength between the tub and the motor mounter is enhanced. Corresponding to the reinforcement rib, the appearance of the seating part provided at the tub may be varied.

When the rotor rotates, a repulsive force of the stator in a circumferential direction may be efficiently supported, because the reinforcement rib 316 extends in a radial direction. Here, the reinforcement rib 316 may be formed by a lancing process. A lancing hole 315 is formed at the plane part 313, corresponding to the reinforcement rib 316.

FIGS. 6 to 9 illustrate the motor mounter formed as one body and the motor mounter is not limited thereto. Specifically, although not shown in the drawings, a plurality of motor mounters may be provided, corresponding to the coupling parts of the stator, respectively. It is preferable that the motor mounters are connected to each other.

In addition, a boss 2 c is formed at a portion where the motor mounter is coupled to reinforce the strength of the portion. As a result, the coupling strength between the tub and the motor mounter may be enhanced by such boss 2 c. Coupling holes are formed at the boss 2 c, and the motor mounter or the stator is coupled to the tub through the coupling hole. As a result, the boss 2 c may be employed to reinforce the strength of such coupling holes. Although not shown in the drawings, a plurality of ribs may be formed near the boss 2 c to reinforce the strength of the boss 2 c. At this time, the boss 2 c and the ribs may be formed as one body with tub 2.

Different from the coupling between the tub and the motor mounter 300 through the bolt T as described above, the motor mounter may be insert-molded in the base 2 a of the tub to be formed as one body with the tub 2. In this case, the process for coupling the motor mounter 300 to the tub 2 may be omitted at work.

The motor mounter shown in FIGS. 6 to 9 may be applicable to such motor mounter. The coupling hole 320 for coupling the motor mounter to the tub may not be needed. When the tub is formed, it may be possible that resin may penetrate through the coupling hole to enhance the coupling strength between the motor mounter and the tub.

In addition, the coupling strength between the motor mounter and the tub may be enhanced through the side surfaces 311 and 312, the lancing hole 315 and the reinforcement rib 316, which are described above.

It is preferable that the coupling hole 310 may be exposed to an outer surface of the tub to facilitate the coupling of the stator to the tub through the motor mounter. For that, only a predetermined portion of the motor mounter may be insert-molded in the tub. Specifically, as shown in FIG. 5, a predetermined portion of the plane part 313 formed at the motor mounter 300 is exposed to the outer surface of the tub. Thus, the coupling hole 310 may be exposed to the outer surface of the tub. It is also possible that the position determination recess 314 is exposed to the outer surface of the tub 2. In this case, the bolt for coupling the motor mounter to the tub is not needed.

Alternatively, as the plane part 313 may be completely insert-molded, only the coupling hole 310 may be exposed to the outer surface of the tub. That is, the coupling hole 310 is projected upward a predetermined distance from the plane part 313 and thus only the coupling hole 310 may be exposed to the outer surface of the tub. For that, a coupling hole having a smaller diameter than is wished is formed primarily and a jig having the wished diameter is pressed to the coupling hole 310 to pass through the coupling hole. As a result, the coupling hole projected upward a predetermined distance from the plane part is formed.

Here, the coupling strength between the motor mounter and the tub may be enhanced because most portion of the motor mounter 300 is insert-molded in the tub.

As mentioned above, considering the facilitation of the tub manufacturing, it is preferable that the predetermined portion of the motor mounter is exposed to the outer surface of the tub when the motor mounter 300 is inert-molded in the tub to be formed as one body with the tub. This is because it is difficult to manufacture the tub if the entire portion of the motor mounter is completely inert-molded in the tub. Specifically, the above exposed portion is supported by a metal mold and thus the motor mounter is inert-molded in the tub easily when the tub is manufactured.

FIG. 10 is a front view illustrating a predetermined portion of the tub base 2 a in a state that most of the motor mounter 300 is insert-molded.

That is, only the coupling hole 310 out of the motor mounter 300 is exposed to the outer surface of the tub and the other portion out of the motor mounter 300 is positioned in the tub. If then, when the tub is manufactured, the motor mounter is formed as one body as the tub. Concentricity between the motor mounter and the tub may be minimized. As a result, concentricity variation may be prevented later.

Because of the motor mounter described above, the tub supporter that is necessary in the conventional drum type washing machine can be omitted and man-hour of assembly line is reduced to improve productivity. Moreover, an overall weight of the drum type washing machine may be reduced by omitting the tub supporter.

On the other hand, the stator 6 configured of the motor, as shown in FIGS. 11 and 12, includes a spiral core SC, an insulator 144, a coil 142 and a coupling part 143. The insulator 144 surrounds the spiral core SC. The coil 142 is wound around each tooth 151 of the spiral core SC. The coupling part 143 is molded as one body with the insulator 144 and it is projected inwardly at more than three portions of the insulator 144. The stator 6 has a weight more than 1.5 kg because of trends for large capacity of drum type washing machines. However, according to the present invention, the stator 6 adapts the spiral core SC and coupled to the tub base 2 a through the insulator 144, which results in reduction of the stator with the same motor performance.

The spiral core SC has a multi-layered structure in which a steel plate is rotated spirally from a bottom layer to a top layer for winding. A tooth 151 is projected outward from a base of the spiral core SC in a radial direction and an insert recess 152 is formed at the base of the spiral core SC to reduce stress produced when winding the core.

The spiral core SC is coupled by a rivet passing through a hole formed at the base 150. A start of the spiral core winding and an end of the spiral core winding are welded at a predetermined portion of the base 150 that contacts with the start and the end.

The insert recess 152 formed at the base 150 of the spiral core SC may be formed in a rectangular or trapezoid shape, or may be formed in an arc shape.

In reference to FIGS. 13 and 14, in the insulator 144 in which more than three coupling parts 143 are projected inwardly from an inner circumferential surface of the core as one body with the insulator 144, the length of each tooth 151 projected from an outer surface of the spiral core SC is referenced to as “a” and the distance from an inner surface of the spiral core SC to a center of a coupling hole 143 a formed at the coupling part 143 is referenced to as “b”. The coupling part 143 is formed with definition of a≧b.

At this time, the coupling part 143 is formed with a height more than 20% of the overall core height. It is preferable that the height of the coupling part 143 is the overall core height.

At least one cavity 143 c is provided on the coupling part 143 to dampen vibration of the motor. A position determination protrusion 143 b is provided on the coupling part 143. Here, the position determination protrusion 143 b is inserted in the position determination recess 314 and it is exposed in a state of being insert-molded in the rear wall of the tub 2.

In addition, a spring pin 143 p or a metal tube is inserted in the coupling hole 143 a to reinforce the strength of the coupling hole 143 a.

Next, an operation of the driving part provided in the drum type washing machine having the above structure will be described.

Electric currents flows at the coil 142 of the stator 6 by control of a controller (not shown) for driving the motor mounted on a panel part to rotate the stator 6. Hence, the shaft 4 serration-connected to the connector 16 connected to the rotor 5 is rotated and the driving force is transmitted to the drum 3 through the shaft 4 to rotate the drum 3.

On the other hand, effects of the drum type washing machine to which the structure of the driving part is applied will be described.

First, the tub 2 of the drum type washing machine according to the present invention is fabricated with plastic material with good heat-insulation. As a result, the drum type washing machine is relatively lighter. The tub is injection-molded. As a result, productivity may be enhanced.

Furthermore, as bearing supporting means, the bearing housing 7 of the drum type washing machine according to the present invention is formed of aluminum alloy. As a result, the bearing housing 7 has no thermo-deformation at relatively high temperatures and it can be applicable to a drum type washing machine having a drying cycle.

When the tub 2 is injection-molded, the metal bearing housing 7 is insert-molded in the hub provided at the rear wall of the tub 2 to be formed as one body with the tub 2. A process for assembling the bearing housing 7 to the rear wall of the tub 2 may be omitted. As a result, assembly process may be simple and thus man-hour may be reduced.

A still further, the stator configured of the motor together with the rotor 5 includes the insert recess 152 formed at the base 150 of the spiral core SC, as shown in FIG. 11, to reduce the stress produced when core winding. As a result, the winding may be performed with a relatively less power.

Especially, as shown in FIG. 13, the stator 6 includes the more than three coupling parts 143 projected inwardly from the inner circumferential surface of the core in a radial direction. The length of each tooth 151 projected from the outer surface of the spiral core SC is referenced to as “a” and the distance from the inner surface of the spiral core SC to the center of the coupling hole 143 a is referenced to as “b” which may be defined into a≧b.

That is, as the position of the coupling hole 143 a is nearer to a portion where load is activated, activating torque is smaller, which is advantageous. However, if the position of the coupling hole 143 a is too nearer to the portion, the diameter of the bolt should be smaller. As a result, too many bolts should be provided to support the stator 6. considering that, the above definition of a≧b is determined.

In reference to FIG. 14, the height of the coupling part 143 is more than 20% of the overall core layered height. If the height of the coupling part 143 is less than 20% of the overall core layered height, vibration produced when the motor is driven is subject to damage the coupling part 143.

Especially, it is preferable that the height of the coupling part 143 is the overall core layered height and it may be higher.

However, if the coupling part 143 is too high, the overall width of the driving part provided in the drum type washing machine. As a result, washing capacity may be decreased. Considering that, the height of the coupling part 143 is not more than twice of the overall core layered height.

A still further, the cavity 143 c formed on the coupling part 143 may dampen the vibration produced when driving the motor, which results in improved mechanical reliability of the stator 6.

In addition, the position determination protrusion 143 b formed on the coupling part 143 is inserted in the position determination recess 314 of the tub 2. As a result, it is easy to couple the stator 6 to the tub 2.

At this time, the cooling pins 133 are formed toward the opening of the rotor 5 by the lancing process. As a result, the through hole 134 formed by the lancing process is employed as a ventilation opening.

Here, the rotor 5 is formed of steel plate and it is molded by the pressing process. As a result, it takes much less time to manufacture the rotor, which results in improved productivity of rotor.

Together with that, the embossing 135 is formed a predetermined portion between each cooling pin 133 and the neighboring cooling pin. As a result, the overall strength of the rotor 5 may be enhanced. The water drain hole 136 is formed on the embossing 35. As a result, water may be drained through the water drain hole.

A still further, the connector 16 is injection-molded with resin material and the vibration mode of the connector 16 is different from the rotor 5 made of steel plate. As a result, the vibration of the rotor 5 is dampened before being transmitted to the shaft 4.

The serration 164 is formed on the inner circumferential surface of the hub formed at the connector 16. As the connector 16 is connected to the serration 400 formed at the rear end of the shaft 4, the rotational force of the rotor 5 is directly transmitted to the shaft through the connector 16.

Next, industrial applicability of the present invention will be described.

The drum type washing machine according to the present invention is a direct motor driven drum type washing machine. As a result, noise, operational failures and power loss may be reduced. Moreover, the bearing housing is made of metal material with no thermo-deformation and thus it is applicable to a drum type washing machine having a drying function.

Furthermore, the drum type washing machine according to the present invention adapts the spiral core SC for easy winding. As a result, original material waste is prevented and it is easy to manufacture a lighter stator with the same performance. It is possible to couple the stator to the tub without the conventional tub supporter for reinforcing the strength of the rear wall of the tub.

A still further, the structure of the driving part provided in the drum type washing machine is improved and the driving force of the motor is directly transmitted to the drum. As a result, noise and operational failures as well as power loss may be reduced and washing efficiency is enhanced to improve production reliability. Moreover, productivity of parts configured of the driving part is enhanced.

A still further, when coupling the stator to the tub, concentricity may be adjusted easily and the adjusted concentricity can be maintained later.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. 

1. A drum type washing machine comprising: a tub mounted in a housing to hold wash water therein; a drum rotatably mounted in the tub; a rotor connected to a rotational shaft of the drum; a bearing housing including a bearing for supporting the rotational shaft of the rotor, the bearing housing positioned at the tub; a stator connected to the tub, spaced apart in a predetermined distance from the rotor; and a motor mounter positioned on a rear surface of the tub, the motor mounter coupled to the stator.
 2. The drum type washing machine of claim 1, wherein the bearing housing is formed as one body with the tub.
 3. The drum type washing machine of claim 2, wherein a hub is projected outwardly at a center of a rear surface of the tub.
 4. The drum type washing machine of claim 3, wherein the bearing housing is positioned at the tub, passing through the hub.
 5. The drum type washing machine of claim 4, wherein unevenness is formed on an outer circumferential surface of the bearing housing and an inner circumferential surface of the tub in a circumferential or extent direction, respectively.
 6. The drum type washing machine of claim 1, wherein the motor mounter is coupled to the tub, spaced apart a predetermined distance from the bearing housing in a radial direction.
 7. The drum type washing machine of claim 6, wherein the motor mounter is ring-shaped.
 8. The drum type washing machine of claim 7, wherein the motor mounter comprises, a ring-shaped plane part; and a side surface projected perpendicularly toward the tub from the plane part.
 9. The drum type washing machine of claim 8, wherein the side surface is formed at on least one of an inner portion or an outer portion of the plane part with respect to a radial direction of the plane part.
 10. The drum type washing machine of claim 7, wherein a coupling part is formed at the stator, coupled to the tub and the motor mounter, and a coupling hole corresponding to the coupling part is formed at the motor mounter.
 11. The drum type washing machine of claim 10, wherein the motor mounter comprises a tub coupling hole coupled to the tub.
 12. The drum type washing machine of claim 11, wherein a seating part is formed at a rear surface of the tub and the motor mounter is seated on the seating part.
 13. The drum type washing machine of claim 12, wherein the seating part has a shape corresponding to the motor mounter.
 14. The drum type washing machine of claim 7, wherein the motor mounter comprises a plurality of reinforcement ribs that extend along a circumferential direction.
 15. The drum type washing machine of claim 14, wherein the motor mounter is formed of a steel plate, further wherein the reinforcing rib is formed by a lancing process.
 16. The drum type washing machine of claim 6, wherein the motor mounter is configured of a plurality of modules.
 17. The drum type washing machine of claim 16, wherein the plurality of the modules are connected each other.
 18. The drum type washing machine of claim 6, wherein at least a predetermined portion of the motor mounter is insert-molded in the tub.
 19. The drum type washing machine of claim 18, wherein an upper portion of the motor mounter is exposed when the motor mounter is insert-molded in the tub.
 20. The drum type washing machine of claim 19, wherein a coupling hole to which the stator is coupled is formed at the motor mounter and the motor mounter is insert-molded, the coupling hole being exposed outside the tub. 